cli: don't defer saves in cli and don't require gtk in cli

docs/installation.md

@@ -24,6 +24,7 @@ Solaar requires Python 3.7+ and requires several packages to be installed.
 If you are running the system version of Python you should have the
 `python3-pyudev`, `python3-psutil`, `python3-xlib`, `python3-evdev`,
 and `python3-yaml` or `python3-pyyaml` packages installed.
+
 To run the GUI Solaar also requires Gtk3 and its GObject introspection bindings.
 If you are running the system version of Python
 the Debian/Ubuntu packages you should have
@@ -31,6 +32,10 @@ the Debian/Ubuntu packages you should have
 in Fedora you need `gtk3` and `python3-gobject`.
 You may have to install `gcc` and the Python development package (`python3-dev` or `python3-devel`,
 depending on your distribution).
+Although the Solaar CLI does not require Gtk3,
+`solaar config` does use Gtk3 capabilities to determine whether the Solaar GUI is running
+and thus should tell the Solaar GUI to update its information about settings
+so it is a good idea to have Gtk3 available even for the Solaar CLI.
 
 If the `hid_parser` Python package is available, Solaar parses HID report descriptors
 and can control more HID++ devices that do not use a receiver.

lib/solaar/cli/config.py

@@ -23,10 +23,6 @@ from logitech_receiver import settings_templates as _settings_templates
 from logitech_receiver.common import NamedInts as _NamedInts
 from solaar import configuration as _configuration
 
-import gi  # isort:skip
-gi.require_version('Gtk', '3.0')  # NOQA: E402
-from gi.repository import Gio, Gtk  # NOQA: E402 # isort:skip
-
 
 def _print_setting(s, verbose=True):
     print('#', s.label)
@@ -188,11 +184,17 @@ def run(receivers, args, find_receiver, find_device):
         return
 
     remote = False
-    if Gtk.init_check()[0]:  # can Gtk be initialized?
-        APP_ID = 'io.github.pwr_solaar.solaar'
-        application = Gtk.Application.new(APP_ID, Gio.ApplicationFlags.HANDLES_COMMAND_LINE)
-        application.register()
-        remote = application.get_is_remote()
+    try:
+        import gi
+        gi.require_version('Gtk', '3.0')
+        from gi.repository import Gio, Gtk
+        if Gtk.init_check()[0]:  # can Gtk be initialized?
+            APP_ID = 'io.github.pwr_solaar.solaar'
+            application = Gtk.Application.new(APP_ID, Gio.ApplicationFlags.HANDLES_COMMAND_LINE)
+            application.register()
+            remote = application.get_is_remote()
+    except Exception:
+        pass
 
     # don't save configuration here because we might want the Solaar GUI to make the change
     result, message, value = set(dev, setting, args, False)
@@ -209,7 +211,6 @@ def run(receivers, args, find_receiver, find_device):
     else:
         if dev.persister and setting.persist:
             dev.persister[setting.name] = setting._value
-            _configuration.save(defer=False)
 
 
 def set(dev, setting, args, save):

lib/solaar/configuration.py

@@ -28,7 +28,6 @@ from threading import Timer as _Timer
 
 import yaml as _yaml
 
-from gi.repository import GLib
 from logitech_receiver.common import NamedInt as _NamedInt
 from solaar import __version__
 
@@ -73,6 +72,7 @@ def _load():
 
 save_timer = None
 save_lock = _Lock()
+defer_saves = False  # don't allow configuration saves to be deferred
 
 
 def save(defer=False):
@@ -86,11 +86,12 @@ def save(defer=False):
         except Exception:
             _log.error('failed to create %s', dirname)
             return
-    if not defer:
+    if not defer or not defer_saves:
         do_save()
     else:
         with save_lock:
             if not save_timer:
+                from gi.repository import GLib
                 save_timer = _Timer(5.0, lambda: GLib.idle_add(do_save))
                 save_timer.start()
 

lib/solaar/gtk.py

@@ -170,6 +170,9 @@ def main():
         else:
             _upower.watch(lambda: listener.ping_all(True))
 
+        import solaar.configuration as _configuration
+        _configuration.defer_saves = True  # allow configuration saves to be deferred
+
         # main UI event loop
         ui.run_loop(listener.start_all, listener.stop_all, args.window != 'only', args.window != 'hide')
     except Exception: